Conventionally, treatment using a stent is performed in which, for example, the stent is indwelled in a stenosed or obstructed portion formed in the body, for example, a tubular organ such as the bile duct, the ureter, the trachea, the blood vessel, or the esophagus, or a body cavity, and the stenosed or obstructed portion is expanded, thereby allowing the bile, the blood, or the like to easily flow, or the stent is indwelled in a portion where an aneurysm occurs, to prevent rupture of the aneurysm from occurring.
In the case where a stent is indwelled in a tubular organ such as the bile duct, with the elapse of time, the inner cavity of the stent may be sometimes closed by body fluid such as the bile, or growth of cancer cells, and a situation in which the stent must be recovered from the body may occur. When such a situation occurs, for example, one end portion of the stent indwelled in the tubular organ is gripped by forceps, a snare, or the like, and then pulled, thereby tearing the stent from the inner wall of the tubular organ, and thereafter the stent is further pulled so as to be extracted from the tubular organ.
As a stent which can be removed from the body, for example, Patent Literature 1 below discloses a stent which has plural annular segments that are formed by bending plural segment struts in a zigzag pattern via mountain- or valley-shaped transition sections, and in which adjacent annular segments are axially coupled to each other via plural connector struts. An eyelet-like head end is disposed in each of mountain-shaped bent portions of the annular segments positioned in one end portion of the stent. When the head end is gripped and pulled, or when a thread or the like is passed through the plural head ends, and the thread is pulled, the stent can be pulled out from the body. Moreover, the mountain-shaped transition sections which are disposed in adjacent annular segments, and which are directed toward the head ends are coupled to each other by the connector struts (see FIG. 1 and amended paragraph [0020]).